Further reduce use of Compiler.closedWorld.

tests/compiler/dart2js/compiler_helper.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library compiler_helper;
 
 import 'dart:async';
 import "package:expect/expect.dart";
 
 import 'package:compiler/src/elements/elements.dart' as lego;
@@ skipping 179 matching lines @@
   lego.LibraryElement lib = compiler.mainApp;
   if (library != null) {
     lib = compiler.libraryLoader.lookupLibrary(library);
     Expect.isNotNull(lib, 'Could not locate library $library.');
   }
   var element = lib.find(name);
   Expect.isNotNull(element, 'Could not locate $name.');
   return element;
 }
 
-types.TypeMask findTypeMask(compiler, String name,
-    [String how = 'nonNullExact']) {
-  var sourceName = name;
-  var element = compiler.mainApp.find(sourceName);
-  if (element == null) {
-    element = compiler.backend.helpers.interceptorsLibrary.find(sourceName);
-  }
-  if (element == null) {
-    element = compiler.commonElements.coreLibrary.find(sourceName);
-  }
-  Expect.isNotNull(element, 'Could not locate $name');
-  switch (how) {
-    case 'exact':
-      return new types.TypeMask.exact(element, compiler.closedWorld);
-    case 'nonNullExact':
-      return new types.TypeMask.nonNullExact(element, compiler.closedWorld);
-    case 'subclass':
-      return new types.TypeMask.subclass(element, compiler.closedWorld);
-    case 'nonNullSubclass':
-      return new types.TypeMask.nonNullSubclass(element, compiler.closedWorld);
-    case 'subtype':
-      return new types.TypeMask.subtype(element, compiler.closedWorld);
-    case 'nonNullSubtype':
-      return new types.TypeMask.nonNullSubtype(element, compiler.closedWorld);
-  }
-  Expect.fail('Unknown TypeMask constructor $how');
-  return null;
-}
-
 String anyIdentifier = "[a-zA-Z][a-zA-Z0-9]*";
 
 String getIntTypeCheck(String variable) {
   return "\\($variable ?!== ?\\($variable ?\\| ?0\\)|"
       "\\($variable ?>>> ?0 ?!== ?$variable";
 }
 
 String getNumberTypeCheck(String variable) {
   return """\\(typeof $variable ?!== ?"number"\\)""";
 }
@@ skipping 42 matching lines @@
     regexp = regexp.replaceAll(xRe, '(?:$anyIdentifier)');
     final spaceRe = new RegExp('\\s+');
     regexp = regexp.replaceAll(spaceRe, '(?:\\s*)');
     if (shouldMatch) {
       Expect.isTrue(new RegExp(regexp).hasMatch(generated));
     } else {
       Expect.isFalse(new RegExp(regexp).hasMatch(generated));
     }
   });
 }